This invention relates to a web roll transferring apparatus, more particularly to a web roll transferring apparatus, for example, in a roll transferring station of a corrugator for producing a corrugated board sheet continuously, which carries out the operation of carrying web rolls to be used as sheet materials to and from between a bogie and a turntable automatically and speedily.
In a corrugator for producing a corrugated cardboard sheet, large amounts of webs are used as a corrugating medium or liners so as to constitute a sheet. Such webs are supplied in the form of rolls having large diameters from paper making plants to corrugated cardboard manufacturing plants. The web rolls are mounted on a group of roll stands disposed at predetermined positions along the corrugator to deliver webs toward a single facer or a double facer. So as to meet demands for the production of various types of products in small lots, the web rolls under delivery are frequently removed from the roll stands and replaced with other types of web rolls on occasion. Such operations of carrying the web rolls in and out of the roll stands are generally achieved by use of a plurality of bogies which run along the rails extended on each side of the roll stands, respectively. Meanwhile, the operations of carrying in and out the web rolls by the bogies and the replacement of web rolls between a plurality of bogies are in many cases performed at a roll transferring station locating upstream the rolls stands (operational side).
For example, FIG. 12 shows perspectively a roll stand 10 used in a corrugator and a roll transferring station S disposed upstream the roll stand 10 This roll stand 10 is of a swing arm system having supported pivotally thereon a pair of longitudinally opposing first arms 12 and a pair of longitudinally opposing second arms 14, and the core paper tubes of web rolls 19 are designed to be chucked removably by the center blocks 16 disposed to the free end portions of the respective arms to oppose each other. On the floor of the corrugated board manufacturing plant, two pairs of rails 18 are extended parallel to each other on each side of the roll stand 10, on which bogies 20 run to reciprocate freely between the roll stand 10 and the roll transferring station S to be described later. By the swinging motion of the arms 12 (14) in the roll stand 10, mounting of the web roll loaded on the bogie 20 stopping beside the roll stand 10 or demounting of the web roll 19 to an empty bogie 20 is achieved. Incidentally, the bogies 20 each have a gentle V-shaped slope on the top surface. The center line l demarcating the V-shape of the slope is designed to extend parallel with the rails 18.
A disc-shaped turntable 24 is disposed so as to be able to rotate horizontally in the roll transferring station S between these two pairs of rails 18. A gentle V-shaped slope is also formed on the top surface of a turntable 24, so that a web roll 19 can stably be loaded thereon. Incidentally, the horizontal rotation of the turntable 24, either manually or mechanically, for example, by a motor, is indexed by 90.degree. between the position where the center line l thereof is parallel to the rails 18 and the position where the center line l is orthogonal to the rails 18.
The operation of transferring the web roll 19 loaded on the bogie 20 to the turntable 24 is generally carried out in the following manner: The bogie 20 with a web roll 19 loaded thereon runs on the rails 18 and stops at a predetermined position in the station S; wherein the center line l of the turntable 24 is indexed in such a way that it may be parallel with the rails 18 (and the center line l of the bogie 20). In such state, the web roll 19 loaded on the bogie 20 is rolled over manually to the turntable 24. While the thus transferred web roll 19 rolls to and fro for a while on the sloped surface of the turntable 24, the rolling of the roll 19 is gradually damped and finally stops. Next, the turntable 24 with the web roll 19 loaded thereon is rotated horizontally by 90.degree. and stopped at the indexed position to allow the center line l of the turntable 24 to be orthogonal with the rails 18. The roll 19 can be carried out by rolling over the web roll 19 manually in the direction indicated by the outlined arrow in FIG. 12.
On the other hand, the operation of transferring the web roll 19 loaded on the turntable 24 onto the bogie 20 is carried out as follows: After the web roll 19 is loaded on the turntable 24 using, for example, a fork lift truck, the turntable 24 is turned by 90.degree. so as to make the center line l thereof parallel with the rails 18. Subsequently, the web roll 19 loaded on the turntable 24 is pushed manually to roll it over to a bogie 20, and then the bogie 20 with the web roll 19 loaded thereon is allowed to run to the position beside the roll stand 10, followed by chucking of the web roll 19 by the arms 12 (or 14).
Incidentally, the web roll 19 itself has a considerable weight, so that it requires an extremely heavy work of an operator to transfer the web roll 19 manually between the turntable 24 and the bogie 20. Thus, as a countermeasure proposed for solving such problem, some corrugators employ a bogie lifting apparatus as shown in FIG. 13. More specifically, the bogie 20 is of a type which can run freely on the rails via wheels 36 as shown in FIG. 13. A protruding piece 21 is disposed on the outer side portion of the bogie 20, which is pushed up or down by means of a hydraulic or pneumatic jack 40 provided on the ground of the factory site around the station S. By operating the jack 40, the bogie 20 is pivoted counterclockwise on the opposite side wheels 36, whereby a required degree of gradient is secured on the top surface of the bogie 20. Thus, the web roll 19 rolls over by its own weight to the turntable 24 locating adjacent thereto. This apparatus, however, involves a danger that the web roll 19 overruns the turntable 24 and drops to the opposite side, since the transference of the web roll 19 to the turntable 24 is achieved instantaneously to gather rolling power. The bogie lifting apparatus suffers a problem that it is absolutely useless when a web roll 19 loaded on the turntable 24 is to be unloaded in the direction indicated by the outlined arrow shown in FIG. 12.
This invention is proposed in view of the above disadvantages inherent in the combination of the turntable and bogies employed in the web roll transferring station and solve them successfully, and it is an object of this invention to provide a roll transferring apparatus which enables automatic unloading (toward upstream) or transference of a web roll loaded on the turntable easily to any of the bogies locating on each side of the turntable, or automatic transference of the web roll loaded on a bogie to the turntable with no fear of overrunning, and which can stop rolling of the web roll immediately after transference.